Solenoid valve assembly

ABSTRACT

A solenoid valve including a spool received within a housing. The spool is configured to move to multiple positions within the housing. The housing includes supply ports, exhaust ports, and outlet ports. When the spool is in a specific location, two outlet ports are in fluid communication with each other.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

The government may own rights in this invention pursuant to grantnumbers N660001-06-8005 JHUAPL from the Department of Defense.

FIELD OF THE INVENTION

The present disclosure relates generally to solenoid valve assembliesused to control the position of a fluid power actuator. The presentdisclosure relates more specifically to solenoid valve assemblies thatrecycle fluid from one portion of the actuator assembly to anotherportion of the actuator assembly.

BACKGROUND INFORMATION

Typical solenoid valve systems utilize a binary-type fluid powerpositioning system in which the solenoid valve is directed to one of twoor three positions. In many existing two-position valves, the solenoidis coupled to an actuator assembly with a double-acting piston. When thesolenoid valve is in the first position, air (or other fluid) isdirected to one side of the piston, while air on the second (opposite)side of the piston is vented to atmosphere. When the solenoid valve isin the second position, air is directed to the second side of thepiston, and air on the first side of the piston is vented to atmosphere.In such examples, essentially the entire volume of air on one side ofthe piston is vented to atmosphere with each piston stroke. Such designstherefore require comparatively high volumes of air to actuate thepiston.

Typical three-position solenoid valve systems operate in a fashionsimilar to the two-position systems described above. However, in certainexamples the solenoid valve can be placed in a third position thateffectively shuts off air to the actuator. As in the case of thetwo-position valve described above, essentially the entire volume of airon one side of the piston is vented to atmosphere with each pistonstroke.

It is therefore desirable to provide a solenoid valve and actuatorsystem that captures a portion of the air that is typically vented toatmosphere during movement of the actuator. The air that is captured canbe directed to the opposing side of the actuator, thereby reducing thevolume of air required to redirect the actuator. It is also desirable toprovide such a solenoid valve that can be retrofitted to replaceexisting solenoid valve systems without extensive modifications.

SUMMARY

Exemplary embodiments of the present disclosure comprise a solenoidvalve system configured to recycle fluid from one side of an actuator toanother side of the actuator when the solenoid valve switches positions.Certain embodiments comprise a system with a housing having: a firstend; a second end; a plurality of ports comprising supply ports, exhaustports, and outlet ports; and a spool received within the housing, wherethe spool is configured to move within the housing from a first positionto a second position and to a third position. In certain embodiments,the second position is between the first position and the third positionand a first outlet port is in fluid communication with a second outletport when the spool is in the second position. In certain embodiments,the first outlet port is adjacent the second outlet port and/or thespool is configured to slide laterally within the housing. In otherembodiments, the spool is configured to rotate within the housing. Incertain embodiments, the system comprises an actuator, wherein theactuator comprises a first side and a second side, and the first outletport is in communication with the first side of the actuator, and thesecond outlet port is in communication with the second side of theactuator.

Certain embodiments comprise a first biasing member configured to exerta first force upon the actuator and a second biasing member configuredto exert a second force upon the actuator. In certain embodiments, whenthe spool is in the first position, a supply port is in fluidcommunication with the first outlet port, and an exhaust port is influid communication with the second outlet port. In certain embodiments,when the spool is in the third position, a supply port is in fluidcommunication with the second outlet port, and an exhaust port is influid communication with the first outlet port.

In certain embodiments, the spool is proximal to the first end of thehousing when the spool is in the first position and the spool isproximal to the second end of the housing when the spool is in the thirdposition. In certain embodiments, the plurality of ports extend throughthe housing, and the spool comprises a plurality of recesses configuredto align with the plurality of ports. In certain embodiments, therecesses extend circumferentially around the spool, while in otherembodiments the recesses extend longitudinally along the spool.

In certain exemplary embodiments, the spool is configured to slidelaterally within the housing to allow a first set of ports to be influid communication with each other when the spool is in the firstposition, a second set of ports to be in fluid communication with eachother when the spool is in the second position, and a third set of portsto be in fluid communication with each other when the spool is in thethird position.

In certain exemplary embodiments, the spool is configured to rotatewithin the housing to allow a first set of ports to be in fluidcommunication with each other when the spool is in the first position, asecond set of ports to be in fluid communication with each other whenthe spool is in the second position, and a third set of ports to be influid communication with each other when the spool is in the thirdposition.

Other exemplary embodiments comprise a system comprising an actuatorassembly and a solenoid valve assembly. In certain embodiments, theactuator assembly comprises: a casing comprising a volume of fluid; anactuator disposed within the casing, wherein the actuator separates thevolume of fluid into a first volume and a second volume; and a solenoidvalve assembly in fluid communication with the actuator assembly. Incertain embodiments, the solenoid valve assembly can be placed in afirst position, a second position, or a third position, and the firstvolume is not in fluid communication with the second volume when thesolenoid valve assembly is in the first position or the third position,and the first volume is in fluid communication with the second volumewhen the solenoid valve assembly is in the second position.

Certain embodiments also comprise a fluid supply system wherein thefluid supply system is in fluid communication with the first volume whenthe solenoid valve assembly is in the first position, and the fluidsupply system is in fluid communication with the second volume when thesolenoid valve assembly is in the third position. In certainembodiments, the solenoid valve assembly comprises a spool configured toslide laterally within the housing, while in other embodiments, thesolenoid valve assembly comprises a spool configured to rotate withinthe housing.

Certain embodiments comprise a system comprising an actuator assemblyand a solenoid valve, where the actuator assembly comprises an actuatorhaving a first volume of fluid on a first side of the actuator and asecond volume of fluid on a second side of the actuator, and thesolenoid valve has a sleeve comprising a plurality of ports. In certainembodiments, the solenoid valve is in fluid communication with theactuator assembly, a first port is in fluid communication with theactuator, a second port is in fluid communication with the actuator, andthe first port is adjacent to the second port. Certain embodiments alsocomprise a fluid supply, a third port in fluid communication with thefluid supply, and a fourth port configured to vent to the environment.In certain embodiments, the actuator comprises a piston, a first springconfigured to engage a first side of the piston, and a second springconfigured to engage a second side of the piston.

In certain embodiments, the solenoid valve comprises a slide memberdisposed within the sleeve, the slide member is configured to slide froma first position proximal to a first end of the sleeve to a secondposition proximal to a second end of the sleeve, and the first port andthe second port are in fluid communication with each other when theslide valve is in a third position between the first position and thesecond position.

Certain embodiments comprise a housing having: an outer surface; aninner surface forming an internal bore; a first end; a second end; asupply port; an exhaust port; a first outlet port; and a second outletport, wherein the supply port, the exhaust port, the first outlet portand the second outlet port each extend from the outer surface of thehousing to the inner surface of the housing. Certain embodiments alsocomprise a sliding member received within the internal bore, wherein thesliding member comprises a plurality of sealing members configured toprevent fluid communication between a pair of adjacent ports; and aplurality of recesses configured to allow fluid communication between apair of adjacent ports, wherein a first recess allows communicationbetween the first outlet port and the second outlet port when thesliding member is positioned at an intermediate position between thefirst end and the second end.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a section view of an exemplary embodiment of asolenoid valve and actuator assembly in a first position.

FIG. 2 illustrates a section view of the embodiment of FIG. 1 in asecond position.

FIG. 3 illustrates a section view of the embodiment of FIG. 1 in a thirdposition.

FIG. 4 illustrates a section view of an exemplary embodiment of asolenoid valve and actuator assembly in a first position.

FIG. 5 illustrates a section view of the embodiment of FIG. 4 in asecond position.

FIG. 6 illustrates a section view of the embodiment of FIG. 4 in a thirdposition.

FIG. 7 illustrates an exploded view of an exemplary embodiment of asolenoid valve assembly.

FIG. 8 illustrates an assembly view of the embodiment of FIG. 7 in afirst position.

FIG. 9-A illustrates a first section view of the embodiment of FIG. 8.

FIG. 9-B illustrates a second section view of the embodiment of FIG. 8.

FIG. 9-C illustrates a third section view of the embodiment of FIG. 8.

FIG. 9-D illustrates a fourth section view of the embodiment of FIG. 8.

FIG. 10 illustrates an assembly view of the embodiment of FIG. 7 in asecond position.

FIG. 11-A illustrates a first section view of the embodiment of FIG. 10.

FIG. 11-B illustrates a second section view of the embodiment of FIG.10.

FIG. 11-C illustrates a third section view of the embodiment of FIG. 10.

FIG. 11-D illustrates a fourth section view of the embodiment of FIG.10.

FIG. 12 illustrates an assembly view of the embodiment of FIG. 7 in athird position.

FIG. 13-A illustrates a first section view of the embodiment of FIG. 12.

FIG. 13-B illustrates a second section view of the embodiment of FIG.12.

FIG. 13-C illustrates a third section view of the embodiment of FIG. 12.

FIG. 13-D illustrates a fourth section view of the embodiment of FIG.12.

FIG. 14 illustrates a section view of the embodiment of FIG. 1 in afourth position.

FIG. 15 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a first position.

FIG. 16 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a second position.

FIG. 17 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a third position.

FIG. 18 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a fourth position.

FIG. 19 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a fifth position.

FIG. 20 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a first position.

FIG. 21 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a second position.

FIG. 22 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a third position.

FIG. 23 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a fourth position.

FIG. 24 illustrates a section view of an exemplary embodiment of asolenoid valve assembly in a fifth position.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring now to FIGS. 1-3, an exemplary embodiment of this disclosurecomprises a solenoid valve 100 comprising a sleeve or housing 110 and asliding member or spool 120. In this embodiment, valve 100 is coupled toan actuator assembly 130 and a fluid supply system 140. In theembodiment shown, actuator assembly 130 comprises a casing 131, anactuator 132 (having a rod 137 and a piston 135), a first biasing member133 and a second biasing member 134. In certain embodiments, first andsecond biasing members 133 and 134 may be compression springs. In theembodiment shown, piston 135 of actuator 132 divides a volume of fluidcontained within casing 131 into two separate volumes (one on each sideof piston 135). While a linear actuator is shown, other embodiments maycomprise different configurations, such as a rotary actuator (notshown). Rotary actuator embodiments may comprise an actuator thatseparates the fluid contained within the casing into two volumes, with afirst side of the actuator in fluid communication with a first volume,and a second side of the actuator in fluid communication with a secondvolume. However, in rotary actuator embodiments, the actuator isconfigured to rotate within the casing rather than slide linearly, andthe biasing members may be torsion springs rather than compressionsprings.

In this exemplary embodiment, fluid supply system 140 comprises areservoir 141. In other embodiments, fluid supply system may comprise acompressor or pump (not shown) configured to compress a fluid and supplyit to reservoir 140. In certain exemplary embodiments, fluid supplysystem 140 may contain air, while in other embodiments, fluid supplysystem may comprise other fluids, including liquids (for example,hydraulic fluid).

In the exemplary embodiment shown, housing 110 comprises a left end 151,a right end 149, an external wall 129, an internal bore 119 and a seriesof ports 111-118 and 121-128 extending through external wall 120 tointernal bore 119. Note that the pair of ports occupying the opposingpositions (111 and 121, 112 and 122, . . . 118 and 128) are connectedvia an external flow path (not shown here) and thus can be taken as thesame port. In this embodiment, exhaust ports 111/121 and 118/128 exhaustto atmosphere, while supply ports 113/123 and 116/126 are coupled tofluid supply system 140 via coupling system 163. In this exemplaryembodiment, outlet ports 112/122, 114/124, 115/125, and 117/127 are influid communication with actuator assembly 130. In other exemplaryembodiments, outlet ports 112/122, 114/124, 115/125, and 117/127 may bein fluid communication with an actuator assembly with a differentconfiguration than that shown in the embodiment of FIGS. 1-3.Non-limiting, exemplary embodiments of other such configurations areillustrated in additional figures in this disclosure. As used herein,the term “outlet port” is generally understood to include any port whichcan be coupled to an actuator to provide fluid communication between theoutlet port and the actuator.

For purposes of clarity in illustration, in FIG. 1 only ports 121-128are shown coupled to external components. As shown in FIG. 1, outletports 122 and 124 are coupled to casing 131 on the left side of piston135 via coupling system 161. Also shown in FIG. 1, outlet ports 125 and127 are coupled to casing 131 on the right side of piston 135 viacoupling system 162. In exemplary embodiments, coupling systems 161, 162and 163 may comprise a system of tubing, piping, or any other well-knownsystem used to provide fluid communication between components.

As shown in FIG. 1, spool 120 comprises an external surface 148comprising a series of reliefs or recesses 145-147. Depending upon theposition of spool 120 within internal bore 119, external surface 148 orrecesses 145-147 will align with one or more ports 111-118 and 121-128.As shown in FIG. 1, spool 120 is disposed towards left end 151 ofhousing 110. In this position, recess 145 aligns with ports 111/121 and112/122 so that they are in fluid communication. In the exemplaryembodiment shown in FIG. 1, recess 146 aligns with port 114/124. Alsoshown in FIG. 1, recess 147 aligns with ports 116/126 and 117/127 sothat they are in fluid communication. In addition, external surface 148aligns with ports 113/123, 115/125, and 118/128 so that each of theseports is isolated from the other ports. In the exemplary embodimentsshown, external surface 148 is a close tolerance fit within internalbore 119 so that fluid is restricted from flowing from ports 113/123,115/125, and 118/128 to other ports. As a result, ports 113/123,115/125, and 118/128 are not in fluid communication with other ports.

As previously mentioned, exhaust ports 111/121 and 118/128 exhaust orvent to atmosphere and outlet ports 112/122 and 114/124 are coupled tocasing 131 on the left side of piston 135 (i.e. the left side of casing131). When spool 120 is in the position shown in FIG. 1, the portion ofcasing 131 on the left side of piston 135 is vented to atmosphere.Therefore, the fluid pressure in the left portion of casing 131 willessentially be atmospheric pressure. As previously mentioned, supplyport 116/126 are coupled to fluid supply system 140, and outlet port117/127 are coupled to the portion of casing 131 to the right of piston135 (i.e. the right side of casing 131). In the position shown in FIG.1, supply port 116/126 is in fluid communication with outlet port117/127; therefore, the right side of casing 131 will be essentially ator near the pressure in fluid supply system 140.

In the embodiment shown in FIG. 1, the pressure in fluid supply system140 is greater than atmospheric pressure. Therefore, the pressure in theright side of casing 131 is greater than the pressure in the left sideof casing 131. As a result of the differential pressure across piston135, it will be moved to the left within casing 131. In the embodimentshown, biasing members 133 and 134 also exert forces on piston 135. Thedifferential fluid pressure across piston 135 compresses biasing member134 (which exerts a force on piston 135 biasing piston 135 to theright). In the position shown in FIG. 1, biasing member 133 may a forceto either the right or left on piston 135.

Referring now to FIG. 2, solenoid valve 100 is shown with spool 120located in an intermediate position between left end 151 and right end149. In this position, recess 145 is aligned with outlet port 112/122,but outlet port 112/122 is isolated from other ports. In addition,recess 147 has aligned with outlet port 117/127, but outlet port 117/127is also isolated from other ports. As shown in the position of FIG. 2,recess 146 has aligned with outlet ports 114/124 and 115/125 so thatthese ports are in fluid communication with each other. As previouslymentioned, outlet port 114/124 is in fluid communication with the leftside of casing 131, and outlet port 115/125 is in fluid communicationwith the right side of casing 131. In the position shown in FIG. 2, theleft side of casing 131 is in fluid communication with the right side ofcasing 131. Also shown in FIG. 2, external surface 148 has blocked offexhaust ports 111/121 and 118/128 which vent to atmosphere. The rightside of casing 131 and the left side of casing 131 are therefore notvented to atmosphere.

Assuming that spool 120 moves from the position shown in FIG. 1 to theposition shown in FIG. 2, fluid will flow from the right side of casing131 to the left side of casing 131. As mentioned in the discussion ofthe embodiment shown in FIG. 1, the left side of casing 131 is atessentially atmospheric pressure and the right side of casing 131 isessentially at the pressure of fluid supply system 140, which is greaterthan atmospheric pressure. As spool 120 moves to the position shown inFIG. 2, the left side of casing 131 is no longer vented to atmosphereand the right side of casing 131 is no longer in fluid communicationwith fluid supply system 140. After spool 120 moves to the positionshown in FIG. 2, the left side of casing 131 is in fluid communicationwith the right side of casing 131. Because the right side of casing 131was initially at a greater pressure than the left side of casing 131,fluid will flow from the right side to the left side of casing 131. Morespecifically, fluid will flow from the right side of casing 131, throughcoupling system 162, outlet port 115/125, recess 146, outlet port114/124, coupling system 161 and to the left side of casing 131. In thismanner, fluid from the right side of casing 131 is redirected orrecycled to the left side of casing 131. This causes the fluid pressureon the right side of piston 131 to decrease and the fluid pressure onthe left side of piston 131 to increase. As the pressure on each side ofpiston 135 approaches equilibrium, biasing member 134 will exert a forceon piston 131 and move it to the right as shown in FIG. 2. In theconfiguration shown in FIG. 2, biasing member 133 is exerting a force onpiston 131 towards the left. However, in certain exemplary embodiments,biasing member 134 can exert a counteracting force great enough toovercome the force of biasing member 133. For example, if biasingmembers 133 and 134 are equivalent compression springs, then biasingmember 134 will exert a greater force than biasing member 133 so long asbiasing member 134 is compressed a greater amount than biasing member133 to compensate for the differential force applied to the piston(because the area on the left side of the piston is smaller than theright side by the area of the piston rod, while the pressure is thesame), so that the piston is in an equilibrium status.

Referring now to FIG. 3, spool 120 of solenoid valve 100 is shown in aposition proximal to right end 149 of housing 110. In this position,recess 146 is aligned with port 115/125, but port 115/125 is isolatedfrom other ports. In addition, recess 147 has aligned with ports117/127, and 118/128 so that port 117/127 (which is coupled to the rightside of casing 131) is vented to atmosphere. In the position shown inFIG. 3, recess 145 has aligned with ports 112/122 and 113/123 so thatport 112/122 (which is coupled to the left side of casing 131) is influid communication with fluid supply system 140. In this position, theleft side of casing 131 is at a higher pressure than the right of casing131 and piston 135 is moved to the right side of casing 131.

Spool 120 can then be moved from the position shown in FIG. 3 to theposition shown in FIG. 2 and the cycle can be repeated. In this manner,piston 135 can be moved within casing 131 based on the position of spool120 within housing 110. Spool 120 can be moved within housing 110 via anelectromagnetic coil (not shown) or by other mechanisms known in the artfor positioning solenoid valves. While housing 110 and spool 120 areshown with a cylindrical configuration in the embodiment shown in FIGS.1-3, other embodiments may have different configurations withcross-sections that are not circular. For example, housing 110 and spool120 may have a cross-section that is shaped like a square or otherpolygon.

Referring now to FIGS. 4-6, an alternative embodiment of a solenoidvalve system 200 comprises a housing 210, a spool 220, an actuatorassembly 230 (having a rod 237 and a piston 235), and a fluid supplysystem 240. Solenoid valve system 200 is generally equivalent tosolenoid valve system 100; however, solenoid valve system 200 comprisesa different number and configuration of ports than solenoid valve system100 and the recesses formed in spool 200 are a different configurationthan those of spool 100. Specifically, the exemplary embodiment shown inFIG. 4 comprises seven ports instead of eight ports. Solenoid valvesystem 200 comprises a single supply port 213/223 coupled to fluidsupply system 240 rather than two supply ports as shown in theembodiment of FIGS. 1-3. Other aspects of solenoid valve system 200 aregenerally equivalent to those of solenoid valve system 100. Therefore,like features and elements in solenoid valve system 200 are identifiedwith similar reference numbers to those used in FIGS. 1-3 (with theexception that reference numbers for FIGS. 4-6 begin with “2” instead of“1”).

As shown in FIG. 4, spool 220 is proximal to left end 251 of housing210. In this position, recess 245 is aligned with exhaust port 211/221and port 212/222 which is in fluid communication with the left side ofcasing 231. Therefore, the left side of casing 231 is generally atatmospheric pressure. Also shown in FIG. 4, recess 246 is aligned withsupply port 213/223 and port 215/225 which is in fluid communicationwith the right side of casing 231. Therefore, the right side of casing231 is generally at the pressure of fluid supply system 240. Also shownin FIG. 4, recess 247 has isolated port 214/224 (which is in fluidcommunication with the left side of casing 231) from the other ports. Inthe configuration shown in FIG. 4, piston 235 is forced to the left sideof casing 231.

Referring now to FIG. 5, spool has moved to a position more centrallylocated between left end 251 and right end 249. In this position, recess245 has isolated port 212/222 and recess 246 has isolated port 215/225.In addition, recess 247 has aligned with port 214/224 (which is in fluidcommunication with the left side of casing 231) with port 217/227 (whichis in fluid communication with the right side of casing 231). As aresult, the left side of casing 231 is in fluid communication with theright side of casing 231 and the differential fluid pressure acrosspiston 235 approaches equilibrium. As a result biasing member 234 biasespiston 235 to the position shown in FIG. 5.

Referring now to FIG. 6, spool 220 is shown in a position proximal toright end 249 of housing 210. In this position, recess 245 is alignedwith supply port 213/223 and left side port 212/222. Recess 246 isaligned with exhaust port 218/228 and right side port 215/225. Alsoshown in FIG. 6, recess 247 is aligned with, and isolates, right sideport 217/227. In this position, the left side of casing 231 is in fluidcommunication with fluid supply system 240 and the right side of casing231 is vented to atmosphere. Piston 235 will be moved towards the rightend of casing 231.

Similar to the embodiment of FIGS. 1-3, the positions shown in FIGS. 4-6can be cycled so that piston 235 is moved from a position near one endof casing 231 towards the other end and back.

Referring now to FIGS. 7-13, an exemplary embodiment of solenoid valvesystem 300 comprises a rotary configuration. Solenoid valve system 300can be coupled to an actuator assembly (not shown) similar to actuatorassembly 130 or 230 in the previously-described embodiments. Solenoidvalve system 300 may also be coupled to a fluid supply system similar tofluid supply system 140 or 240 in the previously-described embodiments.The embodiment of FIGS. 7-13 comprises a housing 310 and a rotary member320 (instead of a spool as shown in the previous embodiments). Rotarymember 320 rotates within housing 310 to align reliefs or recesses345-348 on the external surface of rotary member 320 with ports inhousing 310.

Housing 310 comprises a first end 351 and a second end 329 with a seriesof ports distributed between them. In this specific embodiment, housing310 comprises a series of supply ports 321 proximal to first end 351,and a series of exhaust ports 323 proximal to second end 329. Housing310 further comprises a series of first actuator ports 325 proximal tosupply ports 321 and a series of second actuator ports 322 between firstactuator ports 325 and exhaust ports 323. Housing 310 further comprisesa series of sealing members or ridges 305 between the various ports.Ridges 305 allow one set of ports to be isolated from an adjacent set ofports for purposes of preventing fluid communication between the variousports and external systems (such as actuator systems and fluid supplysystems). For purposes of clarity, not all ridges 305 are labeled inFIGS. 7 and 8.

In the embodiment shown, rotary member 320 comprises a first end 301 anda second end 302. First end 301 comprises an engagement member 303 thatallows a solenoid actuator (not shown) to rotate rotary member 320. Inthis embodiment, rotary member 320 comprises a series of recesses345-348 along its outer surface. Recesses 345 and 347 are approximately180 degrees apart, and are aligned longitudinally (i.e., the recessesare generally the same length and the same distance from first end 301and second end 302). Similarly, recesses 346 and 348 are alsoapproximately 180 degrees apart and aligned longitudinally.

Referring now to FIG. 8, an assembly view of housing 310 and rotarymember 320 is shown with rotary member 320 positioned in a specificposition within housing 310. Specifically, rotary member 320 ispositioned so that first actuator ports 325 are in fluid communicationwith exhaust ports 323 and second actuator ports 322 are in fluidcommunication with supply ports 321. Referring now to FIG. 9-A, asection view taken along line 9-A in FIG. 8 illustrates recesses 345 and347 in alignment with supply ports 321. Referring now to FIG. 9-B, asection view taken along line 9-B in FIG. 8 illustrates recesses 346 and348 are aligned with first actuator ports 325. Referring now to FIG.9-C, a section view taken along line 9-C in FIG. 8 illustrates recesses345 and 347 in alignment with a pair of second actuator ports 322.Finally, referring to FIG. 9-D, a section view taken along line 9-D inFIG. 8 illustrates recesses 346 and 348 are aligned with a pair ofexhaust ports 323.

Therefore, with rotary member 320 in the position shown in FIG. 8, firstactuator ports 325 are in fluid communication with exhaust ports 323(via recesses 346 and 348). In addition, second actuator ports 322 arein fluid communication with supply ports 321 (via recesses 345 and 347).In certain embodiments, a fluid supply system may be in fluidcommunication with supply ports 321, while exhaust ports 323 are ventedto atmosphere. In addition, first actuator ports 325 may be in fluidcommunication with one side of an actuator assembly, while secondactuator ports 322 are in fluid communication with an opposing side ofthe actuator assembly. In such embodiments, placing rotary member 320 inthe position shown in FIG. 8 can move an actuator to one side of theactuator assembly (similar to the position of actuator assembly 130shown in FIG. 1).

Referring now to FIG. 10, rotary member 320 has been rotated so that itis in a different position from that shown in FIG. 8. Specifically,rotary member 320 has been rotated so that first actuator ports 325 arein fluid communication with second actuator ports 322. In addition,supply ports 321 are not in fluid communication with either firstactuator ports 325 or second actuator ports 322. Similarly, exhaustports 323 are not in fluid communication with either first actuatorports 325 or second actuator ports 322.

Referring now to FIG. 11-A, a section view taken along line 11-A in FIG.10 illustrates recesses 345 and 347 are not aligned with any of thesupply ports 321. Referring now to FIG. 11-B, a section view taken alongline 11-B in FIG. 10 illustrates recesses 345 and 347 are in alignmentwith a pair of first actuator ports 325. Also shown in FIG. 11-B,recesses 346 and 348 are aligned with another pair of first actuatorports 325.

Referring now to FIG. 11-C, a section view taken along line 11-C in FIG.10 illustrates recesses 345 and 347 in alignment with a pair of secondactuator ports 322. Also shown in FIG. 11-C, recesses 346 and 348 arealigned with another pair of second actuator ports 322. Finally,referring to FIG. 11-D, a section view taken along line 11-D in FIG. 10illustrates recesses 346 and 348 are not aligned with any of the exhaustports 323.

Therefore, with rotary member 320 in the position shown in FIG. 10,first actuator ports 325 are in fluid communication with second actuatorports (via recesses 345, 346, 347 and 348). In addition, supply ports321 and exhaust ports 323 are not in fluid communication with any ports,and thus are effectively sealed. As previously explained, first actuatorports 325 may be in fluid communication with one side of an actuatorassembly, while second actuator ports 322 are in fluid communicationwith an opposing side of the actuator assembly. In such embodiments,placing rotary member 320 in the position shown in FIG. 10 can move anactuator to an intermediate position in the actuator assembly (similarto the position of actuator assembly 130 shown in FIG. 2).

Referring now to FIG. 12, rotary member 320 has been rotated so that itis in a different position from that shown in FIG. 10. Specifically,rotary member 320 is positioned so that first actuator ports 325 are influid communication with supply ports 321 and second actuator ports 322are in fluid communication with exhaust ports 323. Referring now to FIG.13-A, a section view taken along line 13-A in FIG. 12 illustratesrecesses 345 and 347 in alignment with a pair of supply ports 321.Referring now to FIG. 13-B, a section view taken along line 13-B in FIG.12 illustrates recesses 345 and 347 are aligned with first actuatorports 325. Referring now to FIG. 13-C, a section view taken along line13-C in FIG. 12 illustrates recesses 346 and 348 in alignment with apair of second actuator ports 322. Finally, referring to FIG. 13-D, asection view taken along line 13-D in FIG. 12 illustrates recesses 346and 348 are aligned with a pair of exhaust ports 323.

Therefore, with rotary member 320 in the position shown in FIG. 12,first actuator ports 325 are in fluid communication with supply ports321 (via recesses 345 and 347). In addition, second actuator ports 322are in fluid communication with exhaust ports 323 (via recesses 346 and348). As previously explained, a fluid supply system may be in fluidcommunication with supply ports 321, while exhaust ports 323 are ventedto atmosphere. In addition, first actuator ports 325 may be in fluidcommunication with one side of an actuator assembly, while secondactuator ports 322 are in fluid communication with an opposing side ofthe actuator assembly. In such embodiments, placing rotary member 320 inthe position shown in FIG. 12 can move an actuator the side of theactuator assembly that is opposite from actuator position when rotarymember 320 is in the position shown in FIG. 8 (and similar to theposition of actuator assembly 130 shown in FIG. 3).

While it is understood that the figures contained in this disclosure arenot to scale, the geometry of the various components can be selected toprovide the desired flow dynamics and actuation timing. In theembodiments shown in FIGS. 1-3 and 4-6, outlet ports may be in fluidcommunication with both supply ports and exhaust ports in positionsintermediate to those shown. For example, when spool 120 is in theposition shown in FIG. 14, outlet ports 112/122, 114/124, 115/125, and117/127 are in fluid communication with exhaust port 111/121 and supplyport 116/126. If desired, the spool can be configured so that the outletports are blocked from the exhaust ports and the supply ports during thetransition of spool 120. Referring now to FIG. 15-19, a solenoid valve400 comprises a sliding member or spool 420 within a sleeve or housing410. Solenoid valve 400 is generally equivalent to the embodiment shownin FIGS. 1-3, with the exception that the geometry of external surface448 and recesses 445, 446 and 447 are different. Like elements are givenlike numbers as those shown in FIGS. 1-3, with the exception that thenumbers begin with “4” instead of “1”. Solenoid valve 400 can also becoupled to an actuator system (not shown for purposes of clarity)similar to that shown in FIGS. 1-3. Outlet ports 412/422 and 414/424 aretherefore in fluid communication with one another, as are outlet ports415/425 and 417/427.

As shown in FIG. 15, spool 420 is in the leftmost position, and outletports 412/422 and 414/424 are in fluid communication with exhaust port411/421. In addition, outlet ports 415/425 and 417/427 are in fluidcommunication with supply port 416/426. In the position shown in FIG.16, spool 420 has shifted slightly to the right, and all ports areisolated from each other. As spool 420 shifts further to the right, itreaches the central position shown in FIG. 17, and outlet ports 412/422,414/424, 415/425, and 417/427 are in fluid communication with each other(but isolated from exhaust ports 411/421, 418/428 and supply ports413/423, 416/426). As spool 420 shifts further to the right as shown inFIG. 18, all ports are again isolated from each other. Finally, spool420 reaches the rightmost position shown in FIG. 19, and outlet ports412/422 and 414/424 are in fluid communication with supply port 413/423.In addition, outlet ports 415/425 and 417/427 are in fluid communicationwith exhaust port 418/428. In summary, the embodiment shown in FIGS.15-19 is generally equivalent to that shown in FIGS. 1-3, but thegeometry of spool 420 and external surface 448 (including the length andspacing of recesses 445, 446 and 447) is modified. The modificationsrequire spool 420 to travel a greater distance between the leftmost andrightmost positions and provide isolation of all ports in certainpositions of spool 420.

Referring now to FIGS. 20-24, a modified version of the embodiment shownin FIGS. 4-6 also comprises a spool with greater travel that is capableof isolating all ports when in intermediate positions. Like elements aregiven like numbers as those shown in FIGS. 4-6, with the exception thatthe numbers begin with “5” instead of “2”. Solenoid valve 500 isgenerally equivalent to the embodiment shown in FIGS. 4-6, with theexception that the geometry of external surface 548 and recesses 545,546 and 547 are different.

As shown in the leftmost position of FIG. 20, outlet ports 512/522 and516/526 are in fluid communication with exhaust port 511/521. Inaddition, outlet ports 514/524 and 517/527 are in fluid communicationwith supply port 513/523. As spool 520 moves to the right in theposition shown in FIG. 21, all ports are isolated. When spool 520 movesto the central position shown in FIG. 22, outlet ports 512/522, 514/524,516/526, and 517/527 are in fluid communication (and isolated fromexhaust ports 511/521, 515/525 and supply ports 513/523. As spool 520moves to the right in the position shown in FIG. 23, all ports areisolated. When spool 520 moves to the rightmost position shown in FIG.24, outlet ports 512/522 and 516/526 are in fluid communication withsupply port 513/523. In addition, outlet ports 514/524 and 517/527 arein fluid communication with exhaust port 515/525.

In this disclosure, terms such as “right” and “left” are used forconvenience and clarity with respect to the associated figures. It isunderstood by those skilled in the art, that such descriptions are notlimiting, and that other exemplary embodiments may comprise otherconfigurations (for example, vertical).

While exemplary embodiments are described herein, it will be understoodthat various modifications to the system and apparatus can be madewithout departing from the scope of the present invention. For example,the number of ports may be different in other embodiments.

1-23. (canceled)
 24. A system comprising: a solenoid valve comprising afirst valve position, a second valve position, and a third valveposition; a double-acting piston actuator coupled to the solenoid valve;and a fluid supply system coupled to the double-acting piston actuator,wherein: the fluid supply system comprises a fluid at a pressure greaterthan atmospheric pressure; the double-acting piston actuator comprises afirst cylinder chamber coupled to the solenoid valve via a firstcoupling system; the double-acting piston actuator comprises a secondcylinder chamber coupled to the solenoid valve via a second couplingsystem; the first valve position couples the first cylinder chamber tothe fluid supply system and couples the second cylinder chamber toatmosphere; the second valve position recycles the fluid from firstcylinder chamber through the first coupling system, the solenoid valve,and the second coupling system to the second cylinder chamber; and thethird valve position couples the second cylinder chamber to the fluidsupply system and couples the first cylinder chamber to atmosphere. 25.The system of claim 24, wherein, the solenoid valve comprises: a housingcomprising a plurality of inlet ports, outlet ports, and exhaust ports;and a spool comprising a plurality of recesses; and the second valveposition recycles the fluid through the solenoid valve via a firstoutlet port, a recess, and a second outlet port.
 26. The system of claim25 wherein the first outlet port is adjacent the second outlet port. 27.The system of claim 25 wherein the spool is configured to slidelaterally within the housing.
 28. The system of claim 25 wherein thespool is configured to rotate within the housing.
 29. The system ofclaim 25 wherein the recesses extend circumferentially around the spool.30. The system of claim 25 wherein the recesses extend longitudinallyalong the spool.
 31. The system of claim 24 wherein the double-actingpiston actuator is biased to a mid-stroke position.
 32. The system ofclaim 24, where upon being commanded to move between the first and thirdpositions, the valve dwells in the intermediate second position for aspecified period of time.
 33. The system of claim 32, wherein thespecified period of time for which the valve dwells in the secondposition is preprogrammed and selected to provide sufficient time forthe pressure in the first and second coupling systems to equilibrate.34. The system of claim 32, wherein the system incorporates pressuresensing, and where the specified period of time for which the valvedwells in the second position is based on the pressures measured in thefirst and second coupling systems.
 35. The system of claim 34, whereinthe specified period of time is the length of time required for themeasured pressures in the first and second coupling systems toequilibrate.
 36. The system of claim 34, where the pressure sensing issituated within the valve.
 37. The system of claim 35, where thepressure sensor is a differential pressure sensor that measures thedifferential pressure between the first and second coupling systems. 38.The system of claim 37, wherein the specified period of time is thelength of time required for the differential pressure to essentiallyreach zero.